Final answer:
Sound waves travel fastest through solids due to higher density and closely packed particles, which allows efficient transmission of waves. Solids facilitate sound travel more than liquids, and both are faster than gases. Therefore the correct answer is a) Solids.
Step-by-step explanation:
Sound waves travel through various mediums at different speeds. The speed is dependent on the properties of the medium. Sound waves travel fastest through solids because the particles in solids are closest together, allowing the sound to be transmitted more efficiently.
In contrast, sound travels slower in liquids compared to solids, but faster than in gases.
For example, sound travels faster through steel (a solid) than it does through air (a gas), because steel has a much higher density than air. This is because the molecules in a solid are more tightly packed together, which allows the sound waves to be transmitted from particle to particle more rapidly.
It's important to note that sound cannot travel through a vacuum, as there are no particles to transmit the sound waves.